CFDs are complex instruments and come with a high risk of losing money rapidly due to leverage. 77% of retail investor accounts lose money when trading CFDs with this provider. You should consider whether you understand how CFDs work and whether you can afford to take the high risk of losing your money.
Futures contracts such as Oil and Gas have expiration dates. As soon as it reaches its expiry date, all open positions and orders will be automatically rolled over to the next one.
The rollover is the process of keeping the position open after the expiry date.